1. Field of the Invention
The present invention generally relates to semiconductor integrated circuits, and particularly relates to a semiconductor integrated circuit that manages and controls license information.
2. Description of the Related Art
As the circuit density of semiconductor integrated circuits increases, a semiconductor integrated circuit becomes like a single system including a variety of functions, resulting in a need to properly manage and control the legal right to use each of these functions. For example, it becomes necessary to provide a function to permit or deny the use of a particular function block based on license information. When function blocks subject to intellectual property protection are implemented, there may be a need to calculate royalties according to a period of use or the time of use or to make settings to a valid period of use with respect to these function blocks. Further, when a particular function block is used based on a license, additional license may become necessary to expand the function of the block.
In semiconductor integrated circuits, a function to permit or deny the use of particular function blocks based on license information may be implemented by entering license codes at each start-up operation from an exterior of circuitry and storing them in volatile memory. Operations of the function blocks are then controlled based on the license codes. This method requires the proper management of license codes outside the semiconductor integrated circuits. Further, the number of use needs to be kept record of if there is a need to limit the number of use or the like based on license information, and such a record must be kept outside the device as a precaution against a power failure.
Accordingly, there is a need for a semiconductor integrated circuit that can manage and control license information on its own inside its own circuit.